The Metallurgy of Remendur: Effects of Processing Variations

Historically, considerable difficulty has been experienced in consistently processing the Fe-Co-2.7-wt. percent V alloy (Remendur) into wire with specified magnetic and mechanical properties. A major cause for these problems has been that the metallurgy of this ternary system was not sufficiently understood. A number of investigations have provided information on various aspects of phase equilibria 1-5 and kinetics and mechanisms of phase transformations 6 - 1 0 in this system. 1325 1326 THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1973 The most notable of these are the work of Koster and Schmid 1 on the phase equilibrium of the system and the work of English 6 and Martin and Geisler 2 on the (FCC) (BCC) transformation. However, discrepancies still exist on aspects of phase equilibrium, 1 ' 2,4 ' 7 mechanical ductility, 2,6 ' 7,11 transformation kinetics, 2 ' 6 ' 7 ' 10 and the influence of these factors on the development of magnetic properties.2,6,7,10.12,13 These discrepancies made analysis of the sensitivity of the mechanical and magnetic properties to composition and to heat treating times and temperatures during processing unreliable with further investigation. This anatysis is vital since 2.7-percent V Remendur is being used as the reed material in the remreed contact. 14 This paper describes the characterization of low-vanadium (2-3-wt. percent) Remendur, mainly by light microscopy, for the various processing steps from 6.35-mm (0.25-inch) rod through 0.53-mm (0.021-inch) wire to 0.18-mm (0.007-inch) flattened strip.